This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Multiple microphones can be used to capture efficiently audio events. However, often it is difficult to convert the captured signals into a form such that the listener can experience the event as if being present in the situation in which the signal was recorded. Particularly, the spatial representation tends to be lacking, i.e., the listener does not sense the directions of the sound sources, as well as the ambience around the listener, identically as if he or she was in the original event.
Binaural recordings, recorded typically with an artificial head with microphones in the ears, are an efficient method for capturing audio events. By using stereo headphones the listener can (almost) authentically experience the original event upon playback of binaural recordings. Unfortunately, in many situations it is not possible to use the artificial head for recordings. However, multiple separate microphones can be used to provide a reasonable facsimile of true binaural recordings.
Even with the use of multiple separate microphones, a problem is converting the capture of multiple (e.g., omnidirectional) microphones in known locations into good quality signals that retain the original spatial representation and can be used as binaural signals, i.e., providing equal or near-equal quality as if the signals were recorded with an artificial head.
Furthermore, in addition to binaural output (typically output through headphones), many home systems are able to output over, e.g., five or more speakers. Since many users have mobile devices through which they can capture audio and video (with audio too), these users may desire the option to output sound recorded by multiple microphones on the mobile devices to systems with multi-channel (typically five or more) outputs and corresponding speakers. Still further, a user may desire to use two channel (e.g., stereo) output, since many speaker systems still use two channels.
Thus, a user may wish to play the same captured audio using stereo outputs, binaural outputs, or multi-channel outputs.